Effects of 17beta-estradiol and progesterone on the expression of matrix metalloproteinases and tissue inhibitors of metalloproteinases in rat osteoblasts.

OBJECTIVE

To study the expression of matrix metalloproteinases (MMP) and tissue inhibitors of metalloproteinases (TIMP) in the osteoblasts of SD rats and to assess the change of MMP-2 and TIMP-1 induced by 17beta-estradiol (E2) and progesterone (P), for the purpose of understanding the role of MMP-2 and TIMP-1 in bone resorption.

METHODS

The expression and localization of the MMP-2 in cultured rat osteoblasts were observed immunohistochemically, and MMP-2 and TIMP-1 mRNA expression assayed by reverse transcriptase-polymerase chain reaction (RT-PCR) after the cells were treated with E2 and P at varied concentrations.

RESULTS

MMP-2 protein expression was observed in cultured rat osteoblats, which was inhibited by E2 treatment. The expression of MMP-2 mRNA decreased as doses of E2 and P increased but TIMP-1 underwent no obvious changes.

CONCLUSION

E2 and P can promote the bone formation and slow down the processes of bone matrix degradation and bone resorption by inhibiting the action of MMP-2 in the osteoblasts, and P has the same important effect as estrogen has in the treatment of postmenopausal osteoporosis.